Diagrama de manejo de la densidad para los bosques mezclados de la región de El Salto, Durango

Abstract

Introduction: Density management diagrams (DMDs) are useful tools for characterizing andmanaging stand density. Objective: To develop a DMD to schedule thinnings in the natural mixed-species forests of theEl Salto region, Durango. Materials and methods: The data were collected in 441 temporary sampling plots in 263 mixed-species stands with mainly species of the Pinus and Quercus genus. The DMD was based on theHart-Becking index and a relationship of two allometric equations: 1) the quadratic meandiameter (dg, cm) with the density (N, trees·ha−1) and dominant height (Hd, m), and 2) the volume(V, m3·ha−1) with the dg, Hd and N. In fitting equations, the ordinary Nonlinear Least Squares(NLS) method was used simultaneously. The maximum density limit was estimated by potentialquantile regression that related N to Hd. Results and discussion: Efficient goodness-of-fit statistics were reported in the fitted models, interms of Root Mean Square Error (2.29) and coefficient of determination (0.86). The DMDsuggests applying thinnings below the maximum density line to avoid mortality. Through theDMD it is possible to evaluate different silvicultural alternatives, schedule thinnings, maximizegrowth space, promote tree growth and improve forest products. Conclusion: The DMD developed is useful for thinning scheduling to obtain saw-timber atrotation age